One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,11)(4,7)(5,14)(6,8)(9,12)(10,15)(13,16)(17,18)(19,21)(20,22)(23,27)(24,28)(25,29)(26,32)(30,31) involution — undirected(1,3,5,4,6,12,15,13)(2,7,10,11,8,16,14,9)(17,19,22,29,24,30,23,26)(18,25,27,21,28,32,20,31)(2,8)(3,12)(4,13)(10,14)(17,20,22,18,24,27,23,28)(19,25,29,21,30,32,26,31)(1,4,5,12,6,13,15,3)(2,9,10,7,8,11,14,16)(17,21,23,25,24,31,22,32)(18,26,20,30,28,29,27,19)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.